Information handling devices (“devices”), for example desktop computers, laptop computers, tablets, smart phones, e-readers, etc., ultimately derive their operating power from an external power source or supply. When plugged in or connected to the external power supply, the devices operate using this power, often charging an on-board battery at the same time for later mobile use (in the case of a mobile device).
External power sources come in a variety of forms. Traditionally, the external power source is AC power derived from a commercial power supply, e.g., a wall outlet connected to a public utility. This AC power at the wall outlet is converted in an AC/DC converter and provided to the device. Often the AC/DC converter is in an external component, e.g., power “brick” or converter, e.g., included in a wall plug or adaptor that in turn plugs into the device. This has been a trend driven by the reduced size of many mobile devices such as tablets, smart phones and laptops. However, some other devices, e.g., desktops, retain converter components onboard.
Additionally, rather than a public utility supply, AC power may be supplied by a universal power supply (UPS). Such UPS arrangements are often used in addition to power supplied from a commercial power supply, e.g., to guard against a power failure or utility outage. An example of a UPS is a generator that runs an alternate source of energy (e.g., diesel or natural gas) to charge a battery of the UPS, which then has DC power of the battery converted back into AC power. Converting DC of the UPS battery back to AC output voltage permits devices needing AC to be charged by the UPS while also permitting devices requiring DC power to be charged, e.g., via a plug adaptor or converter—similar to being plugged into the wall outlet.
Conventionally devices attempt to manage power consumption based on the availability of power supply. For example, a device will often be configured to switch a power management setting (or group of settings) to conserve power if integrated battery power supply is detected, with the thought being that the DC power is derived from the device battery and a finite supply of power is thus on hand. Devices conventionally switch to a full power management setting on detecting AC adaptor power.